In recent years, stretchable circuit boards capable of stretching in a curving manner or a planar manner, have been developed. For example, a flexible circuit board (refer to Patent Document 1 listed below) is known as one of these stretchable circuit boards. This flexible circuit board has a stretchable circuit body in which a stretchable insulating base material is provided with a stretchable wiring section. In addition, this flexible circuit board has a non-stretchable component mounting board laminated in a certain region of the stretchable circuit body. Furthermore, this flexible circuit board has an electrical connecting section that electrically connects a wiring section of the component mounting board and the wiring section of the stretchable circuit body.
Moreover, the component mounting board is provided with a stretch-preventing guard that prevents stretching of a region including the electrical connecting section of the stretchable circuit body. As a result, in the flexible circuit board, stretching of a portion of the electrical connecting section in the wiring section of the stretchable circuit body is prevented by the stretch-preventing guard of the component mounting board.